Corsair 2-2-2-5 & A8V works great, but beware...

I build a new system every few years. I'm not an overclocker atheart. For me, stability and reliability are the prime goals. I'llstart by briefly presenting the lessons I've learned from my latestbuild, so that those who already understand such lessons will be ableto skip my rather lengthy story.

Lesson 1) Make sure your RAM is being supplied the correct voltage,especially when using those "special" low latency RAM modules that maybe specified at higher than standard voltages. Your motherboard maynot automatically supply those special voltages.

Lesson 2) Your computer may seem to be running your OS andapplications just fine even if your memory has occasional errors. Youshould test your memory with a good memory testing program, because anapparently fine running machine may have subtle memory errors thatcould, over time, insidiously corrupt your programs and data.

Now for the story behind those lessons:

I recently built a new system (Asus A8V Deluxe, Athlon 64 3500). Justfor the hell of it, and quite out of character for me, I decided totry some low latency ram -- two sets of Corsair TWINX1024-3200XLPT(that's 2GB total). The install of XP Pro went smoothly on the newsystem and everything seemed to be working fine. Later that day Ichecked the RAM timings in BIOS and saw that they were not the 2-2-2-5of the Corsair spec. Instead, the BIOS had set the timings to a morerelaxed spec. I therefore manually changed the BIOS memory timings to2-2-2-5 and rebooted.

Great! Things seemed to be running just fine with the new RAM timing,and my computer was faster too -- a computation of pi to 1 milliondigits now took 2.29 seconds rather than the 2.44 seconds it took withthe previous RAM timings. BTW, exactly what I'll do with those onemillion digits I don't know, but, if you are curious, a Google searchof "Pi Computation" will lead you to some sites that will revealexactly how far computing has come in the past few decades. Now, backto my story.

After playing around with my new machine for a few more hours, Idecided to find a program to better test my RAM. Why? Well, as mostcomputer geeks know, the RAM test at POST is hardly exhaustive.Google lead me to http://www.hcidesign.com where I downloaded theirfree Memtest program. While running the program, I was quitesurprised to find occasional errors reported (about one error per 200MB tested). Not acceptable!

I located the Corsair data sheet for the RAM on their web site and sawthat their timing tests were performed at 2.75 volts. Ah ha! The A8VBIOS had set the RAM voltage to the more standard 2.5 V. Afterchanging the RAM voltage to 2.8 V in BIOS, I ran the Memtest programagain for over an hour with no reported errors. Satisfied that I hadfixed the problem, I then overclocked the machine (CPU + FSB) +5% fora margin test and ran the Memtest again. With no errors reported, Ireturned the computer to the normal clock rate. Margin tests likethat are important because otherwise you wouldn't know if your memorywas just teetering on the edge of failure, as it were.

I think the important lesson here is that if I hadn't decided toperform the memory test, I could have gone for months or even yearswith memory that was generating occasional errors. Surely such errorswould cause problems at some point, but being so rare I might wellhave chalked the problems up to buggy software.

This is an important lesson, I think, for all of us who like to buildour own systems and who sometimes like to push the limits of ourhardware: A seemingly fine running machine may not be so fine afterall. You can't judge a computer's health merely on the fact that itpasses POST, boots the OS day after day, and runs your apps. Checkthat RAM with a good memory testing program and if you get ANY errors,find and fix the problem!

David O wrote:> This is an important lesson, I think, for all of us who like to build> our own systems and who sometimes like to push the limits of our> hardware: A seemingly fine running machine may not be so fine after> all. You can't judge a computer's health merely on the fact that it> passes POST, boots the OS day after day, and runs your apps. Check> that RAM with a good memory testing program and if you get ANY errors,> find and fix the problem!

Indeed.

A good test for CPU stabilty is Prime95 torture test. This tends to throw a fit MUCH sooner than you would notice in just about any other software.

Ben-- A7N8X FAQ: www.ben.pope.name/a7n8x_faq.htmlQuestions by email will likely be ignored, please use the newsgroups.I'm not just a number. To many, I'm known as a String...

GREAT points!!!! especially for new builders as well as some of us that just forget!!

MikeSp--------------------------------------"David O" <nomail@nomail.con> wrote in message news:dhrm111f3fgmrv9jdrljrli4vlhd80dj5c@4ax.com...>>> To all,>> I build a new system every few years. I'm not an overclocker at> heart. For me, stability and reliability are the prime goals. I'll> start by briefly presenting the lessons I've learned from my latest> build, so that those who already understand such lessons will be able> to skip my rather lengthy story.>> Lesson 1) Make sure your RAM is being supplied the correct voltage,> especially when using those "special" low latency RAM modules that may> be specified at higher than standard voltages. Your motherboard may> not automatically supply those special voltages.>> Lesson 2) Your computer may seem to be running your OS and> applications just fine even if your memory has occasional errors. You> should test your memory with a good memory testing program, because an> apparently fine running machine may have subtle memory errors that> could, over time, insidiously corrupt your programs and data.>> Now for the story behind those lessons:>> I recently built a new system (Asus A8V Deluxe, Athlon 64 3500). Just> for the hell of it, and quite out of character for me, I decided to> try some low latency ram -- two sets of Corsair TWINX1024-3200XLPT> (that's 2GB total). The install of XP Pro went smoothly on the new> system and everything seemed to be working fine. Later that day I> checked the RAM timings in BIOS and saw that they were not the 2-2-2-5> of the Corsair spec. Instead, the BIOS had set the timings to a more> relaxed spec. I therefore manually changed the BIOS memory timings to> 2-2-2-5 and rebooted.>> Great! Things seemed to be running just fine with the new RAM timing,> and my computer was faster too -- a computation of pi to 1 million> digits now took 2.29 seconds rather than the 2.44 seconds it took with> the previous RAM timings. BTW, exactly what I'll do with those one> million digits I don't know, but, if you are curious, a Google search> of "Pi Computation" will lead you to some sites that will reveal> exactly how far computing has come in the past few decades. Now, back> to my story.>> After playing around with my new machine for a few more hours, I> decided to find a program to better test my RAM. Why? Well, as most> computer geeks know, the RAM test at POST is hardly exhaustive.> Google lead me to http://www.hcidesign.com where I downloaded their> free Memtest program. While running the program, I was quite> surprised to find occasional errors reported (about one error per 200> MB tested). Not acceptable!>> I located the Corsair data sheet for the RAM on their web site and saw> that their timing tests were performed at 2.75 volts. Ah ha! The A8V> BIOS had set the RAM voltage to the more standard 2.5 V. After> changing the RAM voltage to 2.8 V in BIOS, I ran the Memtest program> again for over an hour with no reported errors. Satisfied that I had> fixed the problem, I then overclocked the machine (CPU + FSB) +5% for> a margin test and ran the Memtest again. With no errors reported, I> returned the computer to the normal clock rate. Margin tests like> that are important because otherwise you wouldn't know if your memory> was just teetering on the edge of failure, as it were.>> I think the important lesson here is that if I hadn't decided to> perform the memory test, I could have gone for months or even years> with memory that was generating occasional errors. Surely such errors> would cause problems at some point, but being so rare I might well> have chalked the problems up to buggy software.>> This is an important lesson, I think, for all of us who like to build> our own systems and who sometimes like to push the limits of our> hardware: A seemingly fine running machine may not be so fine after> all. You can't judge a computer's health merely on the fact that it> passes POST, boots the OS day after day, and runs your apps. Check> that RAM with a good memory testing program and if you get ANY errors,> find and fix the problem!>> Cheers>

Thus spake David O:<Snipped>> Lesson 1) Make sure your RAM is being supplied the correct voltage,> especially when using those "special" low latency RAM modules that may> be specified at higher than standard voltages. Your motherboard may> not automatically supply those special voltages.

Setting *all* FSB, CPU/DDR voltages & memory timings to manual is usually the best approach. Doing so forces one to research more but seems to get stable results with the best performance a lot quicker. Run memtest86 & Prime95 but not /all/ stability problems are caught with either. XP's ACPI Standby mode is shot on my PC at the moment, forcing me to use Hibernate instead. I'll get round to troubleshooting this if the anomaly remains with faster RAM. I've found this forum very informative:http://www.nforcershq.com/forum/viewforum.php?f=13

-- Thank people in advance? Thanking or cursing them afterwards at leastgives some feedback!